Evaluation of commercial 18650 nickel-rich / silicon-graphite batteries for high energy density applications

The demand for energy storage systems is experimenting an important growth in the current days. Applications such as electric vehicles and large-scale energy storage systems are expected to keep growing in the upcoming years. This creates the need for better energy storage systems. Lithium-ion batteries are one of the most widely used due to their advantages in terms of energy density and decreasing cost. However, current state-of-art materials still do not have enough energy density to achieve the desired performance levels in their main applications. To solve this problem, one of the most interesting technologies that has been developed in the recent years is the use of nickel-rich positive electrodes and silicon-graphite negative electrodes. These new technologies can achieve higher energy densities than the current lithium-ion technologies, but their long-term behavior has still not been researched enough. In this paper, two different commercial 18650 cells with nickel-rich positive electrodes and silicon-graphite negative electrodes are evaluated. A test schedule with several aging scenarios and the application of different techniques (incremental capacity analysis and electrochemical impedance spectroscopy) are proposed. The main objective is to evaluate this new battery technology in relation to the current state-of-art technology.